An inverter in a hybrid vehicle supplies electricity required for driving a motor/generator and charges a high-voltage battery with the electricity generated by the motor/generator, between the high-voltage battery and the motor/generator.
Referring to FIG. 1, an inverter 500 includes a capacitor 502, a power module 504 that is constituted by a power conversion switching element, a gate board 506 for driving the power module 504, a control board 510 for controlling torque and speed of a motor/generator 508, and a current measurement device 512 for measuring 3-phase current required for the control. The inverter 500 is connected to a high-voltage battery 514 and the motor/generator 508.
Herein, the capacitor 502 absorbs a switching voltage ripple of the inverter 500 and performs a smoothing operation of suppressing rapid variation of a DC input voltage to allow the inverter 500 to normally operate and increase the durable lifespan of the high-voltage battery.
Typically, a film capacitor having voltage resistance and durable lifespan higher than an electrolytic capacitor is used as the capacitor 502. Although a film capacitor 502 has high voltage resistance and durable lifespan, a film cell in the film capacitor 502 is very vulnerable to temperature. Therefore, a cooling technology becomes a key point.
The inverter 500 may be mounted in a trunk room or an engine room depending on an electric power system of the hybrid vehicle. In the case when the inverter 500 is mounted on an engine room, the temperature of the engine room is very high, it is very important to cool the film capacitor 502 adopted in the inverter 500.
The above information disclosed in this Background Art section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.